1. Field of the Invention
The invention relates to an image forming apparatus or the like such as a copying apparatus or the like and, more particularly, to an image forming apparatus or the like to which a post-processing apparatus and a trimming apparatus are attached and which can execute a binding process.
2. Related Background Art
Hitherto, there has been known an image forming system in which, to an image forming apparatus for reading an image of an original and forming the read image onto a transfer material (paper), a post-processing apparatus for executing a binding process such as stapling process, folding process, sorting process, and the like to the paper on which the image has been formed and a trimming apparatus for executing a cutting process to the sheets of paper subjected to the binding process by the post-processing apparatus are attached.
By attaching such post-processing apparatus and trimming apparatus, not only the operations for the stapling, folding, sorting, and the like of the paper can be lightened but also the bound paper of higher quality can be obtained by cutting overflow portions of the folded and stacked paper obtained after completion of the binding process.
The above conventional image forming system, however, has a problem such that if the sheets of paper subjected to the binding process by the post-processing apparatus are further subjected to the cutting process by using the trimming apparatus, a distance between a paper edge of the paper in a paper bundle obtained after completion of the cutting process and an image forming area, that is, a width of blank portion differs every paper and is not constant, so that binding quality deteriorates.
In consideration of the above conventional problems, it is an object of the invention to provide an image forming apparatus or the like in which when image data to be subjected to a book-binding process is formed onto paper, a width of blank portion does not differ every paper but can be set to be constant, and binding quality can be improved.
To accomplish the above object, according to the invention, there is provided an image forming apparatus comprising: image forming means for visualizing image data and forming it onto transfer materials; post-processing means for executing a post-process including a stapling process, a folding process, and/or a sorting process in order to execute a binding process to the transfer materials on which the image data has been formed; and a trimmer for executing a trimming process to a bundle of the transfer materials subjected to the binding process, wherein when the trimming process by the trimmer is executed, the image forming means sets a non-image forming area including a processing portion (that is, a portion to be processed) to which the trimming process is executed and a valid image forming area excluding the non-image forming area onto the transfer material and forms the visualized data onto the valid image forming area.